High-density detergent composition

ABSTRACT

A high-density detergent composition comprises 10 to 60% by weight of a surfactant composition having a weight ratio of an anionic surfactant to a nonionic surfactant of 4:10 or more and 10:0 or less, wherein the high-density detergent composition has a bulk density of from 600 to 1200 g/L, and has a total summation of a product of a mass base frequency Wi and a dissolving rate Vi of each group of classified granules obtained by classifying detergent granules by using a classifier, which satisfies the following formula: Σ(Wi·Vi)≧95(%), and wherein a mass base frequency of the classified granules having a size of less than 125 μm is 0.1 or less, wherein the classifier comprises sieves each having a sieve-opening 2000 μm, 1410 μm, 1000 μm, 710 μm, 500 μm, 355 μm, 250 μm, 180 μm, and 125 μm, and a receiver.

This application is the national phase under 35 U.S.C. § 371 of PCTInternational Application No. PCT/JP00/00145 which has an Internationalfiling date of Jan. 14, 2000, which designated the United States ofAmerica and was not published in English.

TECHNICAL FIELD

The present invention relates to a high-density detergent compositionand a process for preparing the same.

BACKGROUND ART

While increasing the density of the powdery detergent composition hasimparted great advantages in the improvement in the transportationefficiency and the convenience in the users, there is an increasingconcerning on the dissolubility by compression of the detergentgranules.

While since the mid 1990's, the washing machines have the tendency ofhaving large volume capacity and water conservation by the demands ofusers, and short-period washing mode or gentle stirring mode meeting thedemands of reduction in clothes damaging has been set. However, ineither of the modes, the amount of work (i.e. mechanical power×time) ofthe washing machine tends to be lowered. As a result, there arisecrucial problems that the dissolubility of the detergent granules isdrastically lowered, so that the detergency becomes poor and that theinsoluble remnants deposit on clothes.

On the other hand, Japanese Unexamined Patent Publication Hei 7-509267discloses a detergent composition comprising a base powder comprisinggranules having a size of less than 150 μm in an amount of less than 10%by weight, and granules having a size exceeding 1700 μm in an amount ofless than 10% by weight; and filler granules made of sodium citrate,sodium hydrogencarbonate, or the like. However, the detergentcomposition does not sufficiently solve the problems relating to thedissolubility and the dispersibility of the detergent composition in acase where the amount of work of the washing machine is low.

An object of the present invention is to provide a high-densitydetergent composition which is excellent in the detergency even when theamount of work of the washing machine is low, excellent in thedissolubility of the granules and the dispersibility, and excellent alsoin the hand-washing dissolubility. The above object and other objects ofthe present invention will be apparent from the following description.

DISCLOSURE OF INVENTION

Specifically, the present invention relates to:

(1) a high-density detergent composition (hereinafter referred to as“Detergent Composition I”) comprising 10 to 60% by weight of asurfactant composition having a weight ratio of an anionic surfactant toa nonionic surfactant of 4:10 or more and 10:0 or less, wherein thehigh-density detergent composition has a bulk density of from 600 to1200 g/L, and has a total summation of a product of a mass basefrequency Wi and a dissolving rate Vi of each group of classifiedgranules obtained by classifying detergent granules by using aclassifier, which satisfies the following formula (A):Σ(Wi·Vi)≧95(%)  (A)and wherein a mass base frequency of the classified granules having asize of less than 125 μm is 0.1 or less, wherein the classifiercomprises sieves each having a sieve-opening 2000 μm, 1410 μm, 1000 μm,710 μm, 500 μm, 355 μm, 250 μm, 180 μm, and 125 μm, and a receiver(hereinafter referred to as “classifier”), and the dissolving rate Vi isdetermined under the following measurement conditions (hereinafterreferred to as “measurement conditions for dissolution”):supplying 1.000 g±0.010 g of a sample to 1.00 L±0.03 L of water at 5°C.±0.5° C. having a water hardness of 4° DH, stirring in a 1 L beaker ofwhich inner diameter is 105 mm, with a cylindrical stirring rod of whichlength is 35 mm and diameter is 8 mm, at a rotational speed of 800 rpmfor 120 seconds, and thereafter filtering insoluble remnants by astandard sieve having a sieve-opening of 300 μm as defined according toJIS Z 8801, wherein the dissolving rate Vi of the classified-granules iscalculated by the following formula (a), i being each group of theclassified granules:Vi=(1−Ti/Si)×100(%)  (a)wherein Si is a weight (g) of each group of the classified granulessupplied; and Ti is a dry weight (g) of the insoluble remnants of eachgroup of the classified granules remaining on the sieve afterfiltration; and(2) a high-density detergent composition comprising 10 to 60% by weightof a surfactant composition having a weight ratio of an anionicsurfactant to a nonionic surfactant of 0:10 or more and less than 4:10,the detergent composition having a bulk density of from 600 to 1200 g/L,wherein the high-density detergent composition (hereinafter referred toas “Detergent Composition II”) has a total summation of a product of amass base frequency Wi of each group of classified granules obtained byclassifying detergent granules by using the classifier as defined aboveand a dissolving rate Vi of each group of the classified granulesdetermined under the measurement conditions as defined above, whichsatisfies the following formula (B):Σ(Wi·Vi)≧97(%)  (B)and processes for preparing the same.

Here, the term “mass base frequency” refers to a value obtained bydividing the weight of the classified granules on each sieve or on thereceiver by an entire weight of the detergent composition, theclassified granules being obtained by classifying the detergent granuleswith a classifier.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 (1) and (2) each shows a scheme of classification operation inthe process of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[1] Composition

The surfactant composition in the detergent composition of the presentinvention has a content of from 10 to 60% by weight, preferably from 20to 50% by weight, more preferably from 27 to 45% by weight, of thedetergent composition, from the viewpoints of obtaining the detergencyand the desired powder properties of the detergent composition. Thesurfactant composition comprises an anionic surfactant and/or a nonionicsurfactant, and may also comprise a cationic surfactant and anamphoteric surfactant as occasion demands.

The anionic surfactants include alkylbenzenesulfonates, alkyl or alkenylether sulfates, alkyl or alkenyl sulfates, α-olefinsulfonates,α-sulfofatty acid salts or esters thereof, alkyl or alkenyl ethercarboxylates, salts of fatty acids, and the like. The anionic surfactanthas a content of preferably 1 to 50% by weight, more preferably from 5to 30% by weight of the detergent composition, from the viewpoint of thedetergency.

As the counter ions for the anionic surfactants, the alkali metal ionsare preferable from the viewpoint of improvement in the detergency.Especially, potassium ions are preferable, from the viewpoint of theimprovement in the dissolution rate. The potassium ions are contained inan amount of preferably 5% by weight or more, more preferably 20% byweight or more, particularly preferably 40% by weight or more in theentire counter ions.

The anionic surfactant in the form of potassium salt is prepared by aprocess for neutralizing an acid precursor of the corresponding anionicsurfactant with an alkalizing agent such as potassium hydroxide orpotassium carbonate; a process of carrying out cationic exchange byallowing to coexist in the detergent granules a salt of the anionicsurfactant other than the potassium salt and potassium carbonate.

The nonionic surfactants include polyoxyalkylene alkyl ethers,polyoxyalkylene alkylphenyl ethers, polyoxyalkylene fatty acid esters,polyoxyethylene-polyoxypropylene alkyl ethers, polyoxyalkylenealkylamines, glycerol fatty acid esters, higher fatty acidalkanolamides, alkylglycosides, alkylglucosamides, alkylamine oxides,and the like. From the viewpoint of detergency, polyoxyalkylene alkylethers are preferable, which are ethylene oxide adducts, or a mixtureadduct of ethylene oxide and propylene oxide, each of which alcoholmoiety has 10 to 18 carbon atoms, preferably 12 to 14 carbon atoms, theaverage moles of each alkylene oxide being 5 to 30, preferably 6 to 15.

In addition, the polyoxyethylene-polyoxypropylene-polyoxyethylene alkylether is preferable, from the viewpoints of the detergency and thedissolubility. The compound can be obtained by reacting an ethyleneoxide adduct of which alcohol moiety has 10 to 18 carbon atoms,preferably 12 to 14 carbon atoms with propylene oxide and subsequentlywith ethylene oxide. Further, among the polyoxyethylene alkyl ethersmentioned above, those having a narrow alkylene oxide distribution arepreferable. The compound can be obtained by using a magnesium catalystdescribed in Japanese Patent Laid-Open No. Hei 7-227540 and the like.

The nonionic surfactant has a content of preferably from 1 to 50% byweight, more preferably from 5 to 30% by weight, of the detergentcomposition, from the viewpoint of the detergency.

The cationic surfactants include alkyl trimethylammonium salts, and theamphoteric surfactants include carbobetain-type and sulfobetain-typesurfactants.

In the detergent composition of the present invention, there can beformulated with water-soluble inorganic salts such as carbonates,hydrogencarbonates, silicates, sulfates, sulfites, and salts ofphosphoric acids, from the viewpoint of increasing ionic strength in thewashing liquid. Here, the carbonate is contained, calculated on thebasis of an anhydride, in an amount of preferably 25% by weight or less,more preferably from 5 to 20% by weight, particularly preferably from 7to 15% by weight, of the detergent composition, and a total sum of thecarbonate and the sulfate, calculated on the basis of an anhydride, inan amount of preferably from 5 to 35% by weight, more preferably from 10to 30% by weight, particularly preferably from 12 to 25% by weight, ofthe detergent composition, from the viewpoints of the detergency and thelow-temperature dispersibility under the conditions of allowing thedetergent composition to stand in cold water for a long period of time.

In the detergent composition of the present invention, crystallinesilicates can be formulated. The SiO₂/M₂O molar ratio (wherein M is analkali metal atom) is preferably 0.5 or more, from the viewpoints of themetal ion capturing ability and the anti-hygroscopic property, and themolar ratio is preferably 2.6 or less, from the viewpoint of thealkalizing ability. The molar ratio is particularly preferably from 1.5to 2.2. It is preferable to formulate a crystalline silicate having anaverage particle size of from about 1 to about 40 μm, from theviewpoints of the fast dissolubility and the powder properties, and itscontent is preferably from 0.5 to 40% by weight, more preferably from 1to 25% by weight, of the detergent composition, from the viewpoints ofthe powder properties and the detergency after storage. Especially, itscombined use with sodium carbonate is preferable.

In addition, in the detergent composition of the present invention,there can be formulated organic acid salts such as citrates,hydroxyiminodisuccinates, methylglycine diacetates, glutamatediacetates, aspartate diacetates, serine diacetates,ethylenediaminedisuccinates, and ethylenediaminetetracetates, from theviewpoint of the metal ion capturing ability. Also, it is preferable toformulate a cationic exchange-type polymer having carboxylic acid groupand/or sulfonic acid group, from the viewpoint of the metal ioncapturing capacity and the dispersibility of the solid particle stains.Especially, desirable are salts of acrylic acid-maleic acid copolymershaving a molecular weight of 1000 to 80000; polyacrylates; and salts ofpolyacetal carboxylic acids such as polyglyoxylic acid having amolecular weight of 800 to 1000000, preferably from 5000 to 200000described in Japanese Patent Laid-Open No. Sho 54-52196.

The cationic exchange-type polymer and/or organic acid salt is containedin an amount of preferably from 0.5 to 12% by weight, more preferablyfrom 1 to 10% by weight, still more preferably from 1 to 7% by weight,particularly preferably from 2 to 5% by weight, of the detergentcomposition, from the viewpoint of the detergency.

In addition, the crystalline aluminosilicate such as A-type, X-type, orP-type zeolite can be formulated, and the average primary particle sizeis preferably from 0.1 to 10 μm. Also, an amorphous aluminosilicatehaving an oil-absorbing capacity of 80 mL/100 g or more as determined bythe method in accordance with JIS K 5101 can be formulated, for thepurpose of preventing bleeding out of the liquid components such as thenonionic surfactant. As the amorphous aluminosilicates, for instance,there may be referred to Japanese Patent Laid-Open Nos. Sho 62-191417,Sho 62-191419, and the like. The amorphous aluminosilicate has a contentof preferably from 0.1 to 20% by weight of the detergent composition.

The detergent composition of the present invention can be formulatedwith organic acid salts such as citrates andethylenediaminetetraacetate; dispersing agents or dye-transferinhibitors such as carboxymethyl cellulose, polyethylene glycols,polyvinyl pyrrolidones and polyvinyl alcohols; bleaching agents such aspercarbonates; bleaching activators such as compounds listed in JapanesePatent Laid-Open No. Hei 6-316700 and tetraacetylethylenediamine;enzymes such as protease, cellulase, amylase, and lipase; biphenyl-typeor stilbene-type fluorescent dyes; defoaming agents; antioxidants;blueing agents; perfumes, and the like. Incidentally, granules preparedby separately granulating an enzyme, a bleaching activator, a defoamingagent, and the like may be after-blended.

In addition, as a preferred one embodiment, in the detergent compositionof the present invention, there can be formulated with sodium carbonateand an alkali metal silicate, wherein sodium carbonate is contained inan amount of from 1 to 15% by weight, and a total sum of sodiumcarbonate and the alkali metal silicate (wherein SiO₂/M₂O is from 0.5 to2.6, wherein M is an alkali metal atom) is from 16 to 40% by weight.

It is very important that the sebum stain is washed by laundrydetergent, and it is preferable to formulate an alkalizing agent in ahigh content, for which inexpensive sodium carbonate is widely usable.Especially, when sodium carbonate is contained in the amount specifiedabove, the dispersibility can be even more well maintained withoutforming crystals of hydrates between the detergent granules under thecondition of allowing to stand the detergent composition in cold waterfor a long period of time. Therefore, it is desired that sodiumcarbonate is contained in an amount, calculated on the basis of ananhydride, of 15% by weight or less, preferably from 1 to 15% by weight,more preferably from 5 to 15% by weight, still more preferably from 7 to15% by weight, particularly preferably from 7 to 13% by weight, mostpreferably from 7 to 11% by weight, of the detergent composition.

In addition, sodium carbonate is used in combination with an alkalimetal silicate capable of maintaining excellent low-temperaturedispersibility without forming hydrated crystals between the detergentgranules, in order to obtain excellent detergency. A total sum of thesodium carbonate and the alkali metal silicate is preferably 16% byweight or more, more preferably 19% by weight or more, particularlypreferably 22% by weight or more, and the total sum is more preferablyfrom 40% or less, more preferably 35% by weight or less, particularlypreferably 30% by weight or less, from the viewpoint of thecompositional proportion with other ingredients formulated.

Here, as the alkali metal silicates, there can be used those of eithercrystalline or amorphous forms, and those in a crystalline form arepreferable, from the viewpoint of also having the cationic exchangecapacity.

In the alkali metal silicate, SiO₂/M₂O (wherein M is an alkali metal) ispreferably 2.6 or less, more preferably 2.4 or less, particularlypreferably 2.2 or less, from the viewpoint of the alkalizing ability,and it is preferably 0.5 or more, more preferably 1.0 or more, stillmore preferably 1.5 or more, particularly preferably 1.7 or more, fromthe viewpoint of the storage stability.

Here, as the amorphous alkali metal silicates, there may be used, forinstance, JIS NO. 1, No. 2 sodium silicates; dried granular products ofwater glass such as Britesil C20, Britesil H₂O, Britesil C24, andBritesil H24 (each being registered trademarks trade mark, manufacturedby “The PQ Corporation”). Also, there may be used “NABION 15”(registered trademark, manufactured by RHONE-POULENC), which is acomposite of sodium carbonate and amorphous alkali metal silicate.

The alkali metal silicate has excellent alkalizing ability and cationicexchange capacity comparable to that of 4A-type zeolite by allowing itto crystallize. In addition, the alkali metal silicate is a verypreferable agent from the viewpoint of the low-temperaturedispersibility. Therefore, one or more crystalline alkali metalsilicates which are represented by the following formula (I):x(M₂O).y(SiO₂)z(Me_(m)O_(n)).w(H₂O)  (I)wherein M stands for an element in Group Ia of the Periodic Table,preferably K and/or Na; Me stands for one or more elements selected fromGroup Ia elements, Group IIb elements, Group IIIa elements, Group IVaelements, and Group VIII elements of the Periodic Table, preferably Mgand Ca; y/x is from 0.5 to 2.6; z/x is from 0.001 to 1.0; w is from 0 to20; n/m is from 0.5 to 2.0, and/or represented by the formula (II):M₂O.x′(SiO₂).y′(H₂O)  (II)wherein M stands for an alkali metal element, preferably K and/or Na; x′is from 1.5 to 2.6; and y′ is from 0 to 20, preferably substantially 0,are contained in an amount of preferably from 0.5 to 40% by weight, morepreferably from 1 to 25% by weight, more preferably from 3 to 20% byweight, particularly preferably from 5 to 15% by weight, of thedetergent composition. Here, it is preferable that those in acrystalline form is contained in an amount of 20% by weight or more,more preferably 30% by weight or more, particularly preferably 40% byweight or more, of the alkali metal silicate.

The crystalline alkali metal silicate can be made available, forinstance, under the trade name of “Na-SKS-6” (δ-Na₂O.2SiO₂) fromClariant Japan Co., and those in powdery form and/or granular form maybe used.

Processes for addition of these agents in the preparation process are asfollows. As for adding sodium carbonate, there may be employed a processcomprising adding sodium carbonate to an aqueous slurry, andspray-drying the mixture, thereby powdering the product; a processcomprising adding sodium carbonate adjusted to an average particle sizeof from about 1 to about 40 μm in a granulation step or asurface-modifying step; or a process of after-blending dense ash orlight ash. As for adding an amorphous alkali metal silicate, there maybe employed a process comprising adding an amorphous alkali metalsilicate in an aqueous slurry, and spray-drying the mixture; a processof after-blending the amorphous alkali metal silicate previouslygranulated, and the like. As for adding a crystalline alkali metalsilicate, there may be employed a process comprising adding acrystalline alkali metal silicate adjusted to an average particle sizeof from about 1 to about 40 μm, preferably from about 1 to about 30 μm,more preferably from about 1 to about 20 μm, still more preferably fromabout 1 to about 10 μm in a granulation step or a surface-modifyingstep. During the addition, it is preferable to use in admixture with anagent such as a crystalline and/or amorphous aluminosilicate, from theviewpoint of the storage stability, and the like. In addition, there maybe employed a process of after-blending the granules prepared by aprocess employing a roller compactor disclosed in Japanese PatentLaid-Open No. Hei 3-16442.

In addition, as another preferred embodiment, in the detergentcomposition of the present invention, an anionic surfactant havingsulfuric acid group and/or sulfonate can be formulated in an amount of5% by weight or more to the detergent composition. By the use of theanionic surfactant, the dispersibility among the detergent granules canbe even more excellently maintained under the conditions of allowing thedetergent to stand in cold water for a long period of time. The contentof the anionic surfactant is preferably 5% by weight or more, morepreferably 7% by weight or more, particularly preferably 10% by weightor more. Preferable are alkylbenzenesulfonates, α-olefinsulfonates,α-sulfofatty acid salts or esters thereof, and particularly preferableare alkylbenzenesulfonates.

[2] Bulk Density

The bulk density of the detergent composition determined in accordancewith JIS K3362 is from 600 to 1200 g/L. From the viewpoints ofimprovement in the transportation efficiency and the convenience of theusers, the bulk density is 600 g/L or more, preferably 650 g/L or more,more preferably 700 g/L or more. From the viewpoint of keeping the voidbetween the granules and improving the dispersibility owing to thesuppression of the increase in number of contact between the granules,the bulk density is 1200 g/L or less.

[3] Particle Size Distribution

The detergent composition of the present invention is excellent in thedissolubility per one granule of the detergent granules and thedispersibility (prevention of forming aggregation of the detergentgranules). Here, the dispersibility refers to a phenomenon where afterinitiation of dissolving a part of a surfactant capable of formingliquid crystals and an inorganic salt forming hydrated crystals ofcarbonates, sulfates and the like, the remainder part forms highlyviscous liquid crystals between the detergent granules or recrystallizesinto a hydrate more quickly than being dissolved. Therefore, from theviewpoint of the dispersibility, the particle size distribution of thedetergent composition of the present invention is such that the massbase frequency of the classified granules having a size of less than 125μm in the detergent composition I or II is 0.1 or less or 0.08 or less,respectively.

From the viewpoints of improvements in the dispersibility and theflowability, it is preferable that the content of the fine powder in thedetergent composition is small. The mass base frequency of theclassified granules having a particle size of less than 125 μm is suchthat in the detergent composition I, the mass base frequency of theclassified granules having a size of less than 125 μm is 0.1 or less,preferably 0.08 or less, more preferably 0.06 or less, particularlypreferably 0.05 or less, and that in the detergent composition II, themass base frequency of the classified granules having a size of lessthan 125 μm is 0.08 or less, preferably 0.06 or less, more preferably0.04 or less. In addition, the mass base frequency of the classifiedgranules having a particle size of 125 μm or more and less than 180 μmin both the detergent compositions I and II is preferably 0.2 or less,more preferably 0.1 or less, particularly preferably 0.05 or less. Here,regarding the fine powder, it is preferable that each mass basefrequency satisfies the relationship such that the mass base frequencyof [classified granules having a particle size of less than 125μm]≦[classified granules having a particle size of 125 μm or more andless than 180 μm].

In addition, from the viewpoint of fast dissolubility per one granule,it is preferable that the content of the coarse granules in both thedetergent compositions I and II is small. Specifically, the mass basefrequency of the classified granules having a particle size of 1000 μmor more is preferably 0.03 or less, more preferably 0.01 or less,particularly preferably substantially none. The mass base frequency ofthe classified granules having a particle size of 710 μm or more andless than 1000 μm is preferably 0.1 or less, more preferably 0.05 orless, particularly preferably 0.03 or less. The mass base frequency ofthe classified granules having a particle size of 500 μm or more andless than 710 μm is 0.1 or less, preferably 0.05 or less, morepreferably 0.03 or less. Here, regarding the coarse granules, it ispreferable that each mass base frequency satisfies the relationship suchthat the mass base frequency of [classified granules having a particlesize of 1000 μm or more]≦[classified granules having a particle size of710 μm or more and less than 1000 μm]≦[classified granules having aparticle size of 500 μm or more and less than 710 μm].

The detergent composition of the present invention has an averageparticle size of preferably from 150 μm to 500 μm, more preferably from200 μm to 400 μm, particularly preferably from 250 μm to 350 μm. Here,the average particle size (Dp) is a 50% mass base diameter, and can bedetermined by using the classifier mentioned above. Specifically, afterclassification operation, the mass base frequency is accumulatedsequentially from finer powders to coarser granules. When asieve-opening of a first sieve of which cumulative mass base frequencyis 50% or more is defined as a μm, and a sieve-opening of onesieve-opening larger than a μm is defined as b μm, in a case where thecumulative mass base frequency from the receiver to the a μm-sieve isdefined as c %, and the mass base frequency of granules on the aμm-sieve is defined as d %, the average particle size can be calculatedaccording to the equation (b).Dp=10^(A)  (b)wherein A=[50−(c−d/(log b−log a)×log b)]/[d/(log b−log a)][4] Dissolubility of Classified Granules

In the determination of the dissolubility of each group of theclassified granules, first a sample accurately weighed by using, forexample, an electronic balance “Model ER-180A” manufactured by KenseiKogyo K.K. is supplied evenly so as not to cause aggregation of thegranules and stirred, and thereafter filtered with a standard sievedefined by JIS Z 8801 (sieve-opening: 300 μm) [the sieve having a sievearea of 35 cm² or more and a weight within 10 g is used, and the weightis previously measured]. Subsequently, the insoluble remnants of eachgroup of the classified granules remained on the sieve are subjected todrying operation together with the sieve for 1 hour in an electric dryerat 105° C., and allowed to cool for 30 minutes in a desiccator (25° C.)containing an activated silica gel therein. Thereafter, the weight isdetermined. By subtracting the weight of the sieve from this determinedweight, the dry weight of the insoluble remnants of each group of theclassified granules can be calculated.

The concrete determination conditions are as described as the conditionsfor dissolubility determination described above. Here, the sieve-openingof 300 μm is roughly corresponding to a pore size of a lint filterattached to the washing machine, which means that the high-densitydetergent composition of the present invention can pass through the lintfilter in a very short period of time even with a water temperature of5° C. This means that this detergent composition can satisfactorily meetthe requirements for short time washing modes of the recent washingmachines.

[5] Dissolubility of Detergent Composition

The dissolubility of the detergent composition of the present inventionis expressed by a total summation of a product of a mass base frequencyWi of each group of the classified granules and a dissolving rate Vi ofeach group of the classified granules [namely Σ(Wi·Vi)]. Thedissolubility of the detergent composition I is 95% or more, preferably96% or more, more preferably 97% or more, still more preferably 98% ormore, particularly preferably 99% or more, and the dissolubility of thedetergent composition II is 97% or more, preferably 98% or more, morepreferably 99% or more.

Since the detergent composition of the present invention has extremelyhigh dissolubility markedly distinctive from those of conventionaldetergent compositions, the probability of causing insoluble remnantseven washing under the conditions of super-low mechanical power isextremely low, aside from having such effects that the detergency isincreased by eluting the deterging components more quickly in thewashtub.

[6] Hand-Washing Dissolubility of Detergent Composition

The detergent composition of the present invention also exhibitsremarkably excellent hand-washing dissolubility as compared toconventional detergent compositions. The hand-washing dissolubilityrefers to a measure of the dissolubility when a detergent composition ispreviously dissolved in a vessel such as a washbowl in a case wherestained garments are hand-washed, and expressed by dissolution period oftime. Hand-washing is customarily widely employed washing not only as amatter of course for users whose main washing method is hand-washing butalso as pre-washing of stained clothes for users whose main washingmethod is machine washing. Therefore, the hand-washing dissolubility isimportant as a measure for reflecting a more excellent easy-to-useproperty.

A concrete method for measurement is as follows. In a washbowl (Model“KW-30” washtub manufactured by YAZAKI, inner volume: 8.2 L) made ofpolypropylene having a largest opening diameter of 31 cm, a bottomdiameter of 24 cm and a height of 13 cm was placed 5.0 L of tap water at25° C. Next, 15 g of a detergent composition to be tested is dispersedon entire water surface uniformly and quickly (within 3 seconds or so asa standard) so as not to aggregate in one site. From this point of time,a panelist initiates stirring with one hand (the dominant hand), withwidely stretched five fingers sensing the detergent granules existing atthe bottom of the washbowl with finger tips (inner side of the fingers),in such a manner of gently touching the bottom of washbowl with fingertips. Here, stirring is carried out by repeating each clockwiserotations and counterclockwise rotations alternating with a period of 5rotations. The stirring is carried out so as not to spill the samplesolution from the side wall of the washbowl (the stirring is carried outin about 1.0 second per one rotation, and when reversely rotated, astand-still is held for about 1.0 second as a standard.). In the mannerdescribed above, the stirring is continued until the detergent granulesare no longer sensed, and the period of time is measured. A panelistrepeats a test for a test sample until the deviation of the determinedperiod of time for three runs is within ±5%, and the average period oftime of the three runs is referred to as the period of time for thehand-washing dissolubility of the panelist.

The evaluation is carried out by panelists of 10 or more, and an averagevalue of the period of time for the hand-washing dissolubility for themiddle 60% of the panelists, excluding the top 20% and the bottom 20% ofthe panelists, is referred to as the period of time of the hand-washingdissolubility of the tested detergent composition.

The hand-washing dissolubility of the detergent composition I of thepresent invention is preferably 100 seconds or less, more preferably 80seconds or less, still more preferably 60 seconds or less, still morepreferably 50 seconds or less, still more preferably 40 seconds or less,particularly preferably 30 seconds or less. The hand-washingdissolubility of the detergent composition II of the present invention,which is the same as the detergent composition I, is preferably 100seconds or less, more preferably 80 seconds or less, still morepreferably 60 seconds or less, still more preferably 50 seconds or less,still more preferably 40 seconds or less, particularly preferably 30seconds or less.

[7] Flowability

When the detergent composition of the present invention is placed in awashing machine, it is preferable that its flowability is excellent(more likely to be evenly dispersed) in order to alleviate the loweringof the dispersibility when the composition is in contact with water in acase where the composition is locally gathered together. The flow time(a time period required for dropping 100 mL of powder from a hopper usedin a measurement of bulk density according to JIS K 3362) is preferably10 seconds or shorter, more preferably 8 seconds or shorter, still morepreferably 6.5 seconds or shorter.

[8] Preparation Process

The detergent composition of the present invention can be prepared bysubjecting unclassified detergent granules, comprising 10 to 60% byweight of a surfactant composition, to classification operation andparticle size adjustment operation (the detergent granules beinghereinafter also referred to as “base detergent granules”; here,classified granules obtained by subjecting base detergent granules to aplural times of classification operation and operation for particle sizeadjustment may be also included in the base detergent granules).

(Step 1-1) Preparation Step of Base Detergent Granules of DetergentComposition I

As one embodiment of the process for preparing base detergent granulesusable in the detergent composition I, there can be employed a processcomprising preparing spray-dried particles comprising a surfactant and abuilder, and increasing bulk density. Such a process includes, forinstance, a process comprising stirring and granulating spray-driedparticles in a vertical or horizontal mixer, thereby increasing the bulkdensity. As examples of such processes, there can be employed a processdisclosed in Japanese Patent Laid-Open No. Sho 61-69897, comprisingstirring and granulating spray-dried particles; a process disclosed inJapanese Patent Laid-Open No. Sho 62-169900, comprising forming driedparticles, and thereafter disintegrating and granulating the driedparticles; a process disclosed in Japanese Patent Laid-Open No. Sho62-236897, comprising disintegrating a solid detergent obtained bykneading and mixing detergent raw materials; from the viewpoint ofenergy saving, as a process without using a spray-drying tower, aprocess disclosed in Japanese Patent Laid-Open No. Hei 3-33199,comprising neutralizing in a dry state an acid precursor of an anionicsurfactant with a granular, solid alkalizing agent in a high-speedmixer, and thereafter adding a liquid binder to form granules, and thelike.

(Step 1-2) Preparation Step of Base Detergent Granules of DetergentComposition II

As one embodiment of the process for preparing base detergent granulesusable in the detergent composition I, there can be employed a processdisclosed in Japanese Patent Laid-Open No. Hei 10-176200, comprisinggranulating a mixture comprising a nonionic surfactant, an acidprecursor of an anionic surfactant capable of having a lamellarorientation, and an alkalizing agent, while tumbling with a granulatorat a temperature not less than the temperature capable of neutralizingthe mixture, and the like.

(Step 2) Particle Size Adjustment Step

The base detergent granules are subjected to particle size adjustment,whereby the detergent composition of the present invention can beobtained.

The detergent composition I can be obtained by subjecting base detergentgranules to at least one step of classification operation; thereafterdetermining a mass base frequency for each group of sieve-on classifiedgranules and sieve-pass classified granules against an amount of thebase detergent granules supplied; and blending each group of classifiedgranules such that the formula (A) as defined above is satisfied, andthat a mass base frequency of the classified granules having a size ofless than 125 μm is 0.1 or less. Similarly, the detergent composition IIcan be obtained by blending each group of classified granules such thatthe formula (B) as defined above is satisfied, and that a mass basefrequency of the classified granules having a size of less than 125 μmis 0.08 or less.

In addition, the classification operation may be single-step operationas shown in FIG. 1 (1), or two or more steps of operations as shown inFIG. 1 (2) as occasion demands. A desired detergent composition can beobtained, for instance, by separating coarse granules in the first-stepclassification operation, from the viewpoint of the fast dissolubilityper one granule; separating fine powder, for instance, classifiedgranules having a size of less than 125 μm, in the second-stepclassification operation, from the viewpoint of the low-temperaturedispersibility; and subjecting part or entire fine powder to granulationoperation to be supplied again as the base detergent granules. Theclassification method includes a method employing a circular or sectoralvibration sieve; an ultrasonic vibration sieve comprising the vibrationsieve and an ultrasonic oscillator attached thereto; an air classifieror centrifugal classifier, and the like. In addition, as the blendingmethod, there can be employed a blending method in a batch process witha V-type mixer, or the like, or continuous process.

Incidentally, the determination of the mass base frequency after each ofclassification operation in the classification and particle sizeadjustment steps in (Step 2) is not essential, and the determination canbe omitted as occasion demands. For instance, in the actual preparationstep of the single-step classification operation shown in FIG. 1 (1), ina case of the sieve-on classified granules which are obtained afterseparating and removing fine powder, for instance, classified granuleshaving a size of less than 125 μm, where the formula (A) as definedabove is satisfied and a mass base frequency of granules having a sizeof less than 125 μm is 0.1 or less for the detergent composition I; orin a case of the sieve-on classified granules as described above wherethe formula (B) as defined above is satisfied and a mass base frequencyof granules having a size of less than 125 μm is 0.08 or less for thedetergent composition II, the determination of the mass base frequencyafter the classification operation is omitted, and the sieve-onclassified granules can be used directly as a product. Similarly, in acase of the sieve-pass classified granules which are obtained afterseparating and removing coarse granules, for instance, classifiedgranules having a size of 500 μm or more, where the formula (A) asdefined above is satisfied and a mass base frequency of granules havinga size of less than 125 μm is 0.1 or less for the detergent compositionI; or in a case of the sieve-pass classified granules where the formula(B) as defined above is satisfied and a mass base frequency of granuleshaving a size of less than 125 μm is 0.08 or less for the detergentcomposition II, the determination of the mass base frequency after theclassification operation is omitted, and the sieve-pass classifiedgranules can be used directly as a product. In addition, theseoperations can be combined in multiple steps.

In addition, the detergent composition can be obtained in a high yieldby granulating and/or disintegrating the base detergent granules whichare excess base detergent granules not subjected to particle sizeadjustment; and thereafter reusing as the base detergent granules. Inother words, those granules, like fine powder having a size of less than125 μm having excellent dissolubility per one granule but having aconcern for decreasing the dispersibility of the detergent compositionby an increase in the number of contact between the granules can bereused as base detergent granules after subjecting to a treatment forincreasing particle size such as granulation operation. It is especiallyimportant for the detergent composition of the present invention thatthe mass base frequency of the classified granules having a size of lessthan 125 μm is reduced, and the process becomes economicallyadvantageous by carrying out the above operations. On the other hand,excess coarse granules which are poor in the dissolubility per onegranule can be reused as base detergent granules after subjecting thecoarse granules to a treatment for decreasing particle size such asdisintegration operation.

Specifically, in the detergent composition I, the classified granulesnot used in Steps 1-1 or 1-2 and 2 mentioned above can be preferablyreused as base detergent granules in reference to the dissolving rateVi, in a case where, for instance, fine powder having Vi of 95% or moreis subjected to granulation operation, or coarse granules having Vi ofless than 95% are subjected to disintegration operation. Similarly, inthe detergent composition II, fine powder having Vi of 97% or more issubjected to granulation operation, or coarse granules having Vi of lessthan 97% are subjected to disintegration operation, whereby the granulesare preferably reused as base detergent granules. The fine powdergranulation operation and the coarse granules disintegration operationare exemplified below.

(Fine Powder Granulation Operation)

Excess fine powder may be collected by adding them in the form of finepowder without treatment during the preparation process of Step 1-1 or1-2 for the base detergent granules. In addition, as an alternativecollecting method, for instance, the excess fine powder may be collectedby a process comprising compressing and granulating in a vertical orhorizontal granulator; an extruding granulation process employing anextruder; a compression-granulation method such as briquetting, and thelike. In addition, a binder can be added during granulation.

(Coarse Granules Disintegration Step)

Excess coarse granules can be reused as base detergent granules by, forinstance, disintegrating the coarse granules, thereby decreasing theirparticle size. The disintegrator for coarse granules includes impactcrushers such as hammer crusher; impact pulverizers such as atomizersand pin mills; shearing rough pulverizers such as flash mills. Thesedisintegrators may comprise single-step operation, or multi-stepoperations with the same or different disintegrators. Incidentally, itis preferable to add fine powder as an agent for controlling depositionwithin devices or as a surface-modifying agent for pulverized surfaces.The fine powder is preferably inorganic powders such asaluminosilicates, silicon dioxide, bentonite, talc and clay amorphoussilica derivatives, and especially, crystalline or amorphousaluminosilicates are preferable. In addition, fine powders of inorganicsalts such as sodium carbonate and sodium sulfate can be used.

In addition, for the purpose of coating and smoothening asurface-modifying agent for improving flowability of the disintegratedgranules, a surface-modifying step can be provided in the process. Forinstance, there may be employed the process comprising supplying acomposition in a batch process or continuous process into a rotatablecylindrical mixer or an agitator, thereby subjecting the composition totumbling or stirring treatment.

By the combination of the fine powder granulation operation and thecoarse granules disintegration operation, the detergent composition canbe obtained in a high yield from the excess classified detergentgranules in Step 2. In addition, after the classification and particlesize adjustment steps, there can be formulated enzymes, dyes, perfumes,and the like.

Evaluation 1 [Dissolubility of Detergent] A lint filter (model number:AXW22A-5RU0, pore-size: 300×640 μm) was attached to a side wall portionof a washtub of a washing machine “AISAIGO NA-F70VP1” manufactured byMatsushita Electric Industrial Co., Ltd. Next, 3 kg of clothes (cottonunderwear: 50% by weight, dress shirt made of mixed fabric ofpolyester/cotton: 50% by weight) were placed thereinto, and thereafter44.0 g of each detergent composition of Examples was uniformlydispersed. Tap water at 5° C. was poured thereinto, and washing wascarried out by a setting of “standard course: 3 minutes washing and highwater level (66 L).” After termination (without including rinsing step),the amount of the detergent remained in the lint filter was visuallydetermined by the following evaluation criteria. The water temperatureat 5° C. was a disadvantageous condition for the dissolubility of thegranules, so that the evaluation results A, B and C indicated excellentdissolubility of the granules.

[Evaluation Criteria]

-   A: The remnants of the detergent granule being almost zero (estimate    number of remained detergent granules: 0 to 5 granules);-   B: No remnant detergent granules (estimate number of remained    detergent granules: 6 to 15 granules);-   C: Substantially no remnant detergent granules (estimate number of    remained detergent granules: 16 to 30 granules);-   D: The remnants of detergent granules being in small amounts    (estimate number of remained detergent granules: 30 to 100    granules);-   E: The remnants of detergent granules being in large amounts    (estimate number of remained detergent granules: 101 or more, the    remnants of paste being also scattered).    Evaluation 2 [Dispersibility of Detergent] The amount 25.0 g of each    detergent composition of Examples was placed in an aggregated state    near the outer periphery of one of the dents of a sector, a    six-divided section of a pulsator of washing machine “AISAIGO    NA-F42Y1” manufactured by Matsushita Electric Industrial Co., Ltd.    The amount 1.5 kg of the clothes (the same as in Evaluation 1) was    placed in the washtub, without disintegrating the agglomeration.    Twenty-two liters of tap water at 5° C. was poured thereto at a flow    rate of 10 L/min such that the water would not directly hit the    detergent. After the termination of water-pouring, the aqueous    mixture was allowed to stand. After 3 minutes from the start of    water-pouring, the stir was started with gentle water flow    (handwashing-mode). After stirring for 3 minutes, water was    discharged, and the states of detergents remained on the clothes and    the washtub were visually determined by the following evaluation    criteria. The stir strength of this evaluation was very weak as    compared to that of the standard mode, so that the evaluation    criteria I and II indicated excellent dispersibility. In addition,    the term “aggregates” described below refers to a mass of aggregated    detergent granules having a diameter of 3 mm or more.    [Evaluation Criteria]-   I: No aggregates;-   11: Substantially no aggregates (1 to 5 masses having a diameter of    about 3 mm being found);-   III: Aggregates remaining in small amounts (masses having a diameter    of about 6 mm being found, and 10 or less masses having a diameter    of from 3 to 10 mm being found); and-   IV: Aggregates remaining in large amounts (a large number of masses    having a diameter exceeding 6 mm being found).    Evaluation 3 [Detergency of Detergent] An artificial soil solution    having the following compositions was smeared to a cloth to prepare    an artificially stained cloth. The smearing of the artificial soil    solution to a cloth was carried out in accordance with Japanese    Patent Laid-Open No. Hei 7-270395 wherein the artificial soil    solution was printed on a cloth by a gravure staining machine    equipped with a gravure roll coater. The process for smearing the    artificial soil solution to a cloth to prepare an artificially    stained cloth was carried out under the conditions of a cell    capacity of a gravure roll of 58 cm³/cm², a coating speed of 1.0    m/min, a drying temperature of 100° C., and a drying time of one    minute. As to the cloths, #2003 calico (manufactured by Tanigashira    Shoten) was used.    (Composition of Artificial Soil Solution)

Lauric acid: 0.44% by weight (hereinafter “%”), myristic acid: 3.09%,pentadecanoic acid: 2.31%, palmitic acid: 6.18%, heptadecanoic acid:0.44%, stearic acid: 1.57%, oleic acid: 7.75%, triolein: 13.06%,n-hexadecyl palmitate: 2.18%, squalene: 6.53%, lecithin, from egg:1.94%, Kanuma red clay: 8.11%, carbon black: 0.01%, and tap water:balance.

(Detergent Conditions and Evaluation Method)

The amount 2.2 kg of clothes (underwear and dress shirt in a proportionof 8/2) and 10 pieces of the artificially stained cloths of 10 cm×10 cmsewn on to 3 pieces of cotton support cloths of 35 cm×30 cm were evenlyplaced in a washing machine “AISAIGO NA-F40AP” manufactured byMatsushita Electric Industrial Co., Ltd. Twenty-two grams of eachdetergent composition was placed on the clothes in an aggregated state,and water was poured thereto such that the water would not directly hitthe detergent. The washing was carried out under the standard course.The washing conditions are as follows.

Washing course: standard course; detergent concentration: 0.067%; waterhardness: 2.7° DH; water temperature: 5° C.; liquor ratio: 15 L/kg.

The detergency was evaluated by measuring the reflectance at 550 nm ofthe unstained cloth and those of the stained cloth before and afterwashing by an automatic recording calorimeter (manufactured by ShimadzuCorporation), and the detergency (%) was calculated by the followingequation. The average value determined of 10 pieces was expressed as thedetergency.Detergency(%)=(Reflectance of Cloth After Washing−Reflectance of StainedCloth Before Washing)/(Reflectance of Unstained Cloth−Reflectance ofStained Cloth Before Washing)×100Evaluation 4 [Hand-Washing Dissolubility] The hand-washing dissolubilitywas determined by the measurement method described above. As for thewashbowl, the Model KW-30 washtub manufactured by YAZAKI was used, andthe hand-washing dissolubility was measured by 10 panelists.

PREPARATION EXAMPLE 1 Parts by Weight being Hereinafter Expressed as“Parts”

Twenty-five parts of a sodium linear alkyl(10 to 13 carbonatoms)benzenesulfonate; 3 parts of a sodium alkyl(12 to 16 carbonatoms)sulfate; 2 parts of a polyoxyethylene (average moles of EO: 8)alkyl(12 to 14 carbon atoms) ether (hereinafter referred to as “nonionicsurfactant”); 3 parts of a soap (14 to 20 carbon atoms); 10 parts ofzeolite 4A; 9 parts of No. 1 sodium silicate; 10 parts of sodiumcarbonate; 2 parts of potassium carbonate; 1.5 parts of sodium sulfate;0.5 parts of sodium sulfite; 1 part of sodium polyacrylate (averagemolecular weight: 10,000); 3 parts of an acrylic acid-maleic acidcopolymer (Sokalan CP5); 1.5 parts of a polyethylene glycol (averagemolecular weight: 8,500); and fluorescent dyes (0.1 parts of TinopalCBS-X and 0.1 parts of WHITEX SA) were mixed with water to prepare aslurry having a solid ingredient of 50% by weight (temperature: 65° C.).The resulting slurry was dried by using a countercurrent flow typespray-dryer to give particles having a bulk density of about 300 g/L.The content of volatile matter was 4% (amount lost at 105° C. for 2hours). Subsequently, 78 parts of the granules and 3 parts of zeolite 4A(average particle size: about 3 μm) were introduced into a High-SpeedMixer (manufactured by Fukae Powtec Corp., volume capacity: 25 L), andmixed. Thereafter, 5 parts of crystalline silicate powders (pulverizedproduct of SKS-6, average particle size: 27 μm) were introduced into themixer, and the mixture was further pulverized and granulated withstirring, while spraying 4 parts of the above nonionic surfactantthereto. In this process, 5 parts of the above powdery zeolite was addedfor surface-coating immediately before the termination of the process,to give base detergent granules (1). The entire charged amount was 5 kg.

PREPARATION EXAMPLE 2

Fourteen parts of a potassium linear alkyl(10 to 13 carbonatoms)benzenesulfonate; 8 parts of a sodium salt of methyl ester ofα-sulfofatty acid (14 to 16 carbon atoms); 1 part of the same nonionicsurfactant as in Preparation Example 1; 7 parts of the same soap as inPreparation Example 1; 10 parts of zeolite 4A; 1 part of No. 1 sodiumsilicate; 5 parts of sodium carbonate; 16 parts of potassium carbonate;1.1 parts of sodium sulfate; 1.5 parts of sodium sulfite; 2 parts of thesame sodium polyacrylate as in Preparation Example 1; 2 parts of thesame polyethylene glycol as in Preparation Example 1; and fluorescentdyes (0.2 parts of Tinopal CBS-X and 0.1 parts of WHITEX SA) were mixedwith water to prepare a slurry having a solid ingredient of 48% byweight (temperature: 65° C.). The resulting slurry was dried by using acountercurrent flow type spray-dryer to give particles having a bulkdensity of about 320 g/L. The content of volatile matter was 3% (amountlost at 105° C. for 2 hours). Subsequently, 50 kg/H of the aboveparticles, 4 kg/H of sodium carbonate (heavy ash), 1 kg/H of the samecrystalline silicate powders as in Preparation Example 1, and 3 kg/H ofthe same nonionic surfactant as in Preparation Example 1 werecontinuously supplied to a continuous kneader (manufactured by KurimotoTekkosho K.K.). The resulting mixture was pelletized by using atwin-screw extruder (“PELLETER DOUBLE,” manufactured by Fuji Paudal Co.,Ltd.) arranged at the discharge outlet of the kneader to givecylindrical pellets having a diameter of about 3 mm. Five parts ofpowdery zeolite (average particle size: about 3 μm) was added as an aidagent for pulverizing, based on 100 parts of the pellets, and themixture was pulverized and granulated by a Fitz Mill (manufactured byHosokawa Micron Corporation) equipped with a screen having a 1.5mm-sieve opening with aeration of cool air at 14° C.

PREPARATION EXAMPLE 3

Twenty-four parts of a sodium linear alkyl(10 to 13 carbonatoms)benzenesulfonate; 4 parts of the same sodium alkylsulfate as inPreparation Example 1; 4 parts of the same nonionic surfactant as inPreparation Example 1; 1 part of a soap (14 to 20 carbon atoms); 14parts of No. 1 sodium silicate; 14 parts of sodium carbonate; 4 parts ofsodium sulfate; 4 parts of the same acrylic acid-maleic acid copolymeras in Preparation Example 1; 1 part of the same polyethylene glycol asin Preparation Example 1; and fluorescent dyes (0.1 parts of TinopalCBS-X and 0.1 parts of WHITEX SA) were mixed with water to prepare aslurry having a solid ingredient of 50% by weight (temperature: 63° C.).The resulting slurry was dried by using a countercurrent flow typespray-dryer to give particles having a bulk density of about 300 g/L.The content of volatile matter was 2.5% (amount lost at 105° C. for 2hours). Subsequently, 70 parts of the above particles, 7 parts ofpowdery zeolite (average particle size: about 3 μm), and 5 parts of thesame crystalline silicate as in Preparation Example 1 were blended byusing a ribbon blender. The mixture was compressed to regulate its sizesat a roll pressure of about 1 MPa by a Chilsonator (manufactured by FujiPaudal Co., Ltd., roll width: 102 mm, roll diameter: 254 mm), and theresulting granules were classified with a sieve having a 1,410 μm-sieveopening. The coarse granules of 1,410 μm or more were pulverized by aFitz Mill using powdery zeolite as an aid agent for pulverizing, andthereafter mixed with sieve-pass granules, to give base detergentgranules.

PREPARATION EXAMPLE 4

Fifteen parts of zeolite 4A; 5 parts of sodium sulfate; 2 parts ofsodium sulfite; and 2 parts of the same sodium polyacrylate as inPreparation Example 1 were mixed with water to prepare a slurry having asolid ingredient of 50% by weight (temperature: 58° C.). The resultingslurry was spray-dried by using a countercurrent flow type spray-dryer.The content of volatile matter of the particles was 2% (amount lost at105° C. for 2 hours). Twenty parts of the same nonionic surfactant as inPreparation Example 1; 3 parts of the same polyethylene glycol as inPreparation Example 1; and 7 parts of palmitic acid were mixed withheating at 75° C. to prepare a liquid mixture. Subsequently, 25 parts ofthe above particles, 40 parts of crystalline silicate (pulverizedproduct of SKS-6, average particle size: 17 μm), and 5 parts ofamorphous aluminosilicate (average particle size: 10 μm, disclosed inJapanese Patent Laid-Open No. 6-179899) were introduced into a LödigeMixer (manufactured by Matsuzaka Giken Co., Ltd., volume capacity: 20 L,equipped with a jacket), and the stirring with the main shaft (150 rpm)and the chopper (4,000 rpm) was started. The above liquid mixture wassupplied to the mixer and was sprayed onto the powder mixture in 2.5minutes, and thereafter stirred for 6 minutes. Further, 3 parts of theamorphous aluminosilicate was supplied as a surface-coating agent to themixer, and the mixture was stirred for 1.5 minutes, to give basedetergent granules. The entire charged amount was 4 kg.

PREPARATION EXAMPLE 5

Twenty-five parts of a sodium linear alkyl(10 to 13 carbonatoms)benzenesulfonate; 4 parts of a sodium alkyl(12 to 16 carbonatoms)sulfate; 2 parts of the same nonionic surfactant as in PreparationExample 1; 3 parts of a soap (14 to 20 carbon atoms); 12 parts ofZeolite P; 8 parts of No. 2 sodium silicate; 10 parts of sodiumcarbonate; 2 parts of potassium carbonate; 2 parts of sodium sulfate;0.5 parts of sodium sulfite; 5 parts of the same acrylic acid-maleicacid copolymer as in Preparation Example 1; 1 part of the samepolyethylene glycol as in Preparation Example 1; and fluorescent dyes(0.1 parts of Tinopal CBS-X and 0.1 parts of WHITEX SA) were mixed withwater to prepare a slurry having a solid ingredient of 50% by weight(temperature: 65° C.). The resulting slurry was dried by using acountercurrent flow type spray-dryer to give particles having a bulkdensity of about 310 g/L. The content of volatile matter was 4% (amountlost at 105° C. for 2 hours). Thereafter, 78 parts of the particles and3 parts of Zeolite P (average particle size: about 3 μm) were introducedinto a High-Speed Mixer (manufactured by Fukae Powtec Corp., volumecapacity: 25 L), and mixed. Subsequently, the resulting mixture waspulverized and granulated with stirring, while spraying 4 parts of apolyoxyethylene (average moles of EO: 6) alkyl(12 to 14 carbon atoms)ether. In this process, 5 parts of the above powdery zeolite was addedfor surface-coating immediately before the termination of the process,to give base detergent granules. The entire charged amount was 5 kg.

PREPARATION EXAMPLE 6

Twenty-five parts of a sodium linear alkyl(10 to 13 carbonatoms)benzenesulfonate; 4 parts of a sodium alkyl(12 to 16 carbonatoms)sulfate; 2 parts of a polyoxyethylene (average moles of EO: 6)alkyl(12 to 14 carbon atoms) ether; 3 parts of a soap (14 to 20 carbonatoms); 10 parts of zeolite 4A; 3 parts of No. 1 sodium silicate; 20parts of sodium carbonate; 2 parts of potassium carbonate; 1 part ofsodium sulfate; 0.5 parts of sodium sulfite; 5 parts of the same acrylicacid-maleic acid copolymer as in Preparation Example 1; 1 part of thesame polyethylene glycol as in Preparation Example 1; and fluorescentdyes (0.1 parts of Tinopal CBS-X and 0.1 parts of WHITEX SA) were mixedwith water to prepare a slurry having a solid ingredient of 50% byweight (temperature: 65° C.). The resulting slurry was dried by using acountercurrent flow type spray-dryer to give particles having a bulkdensity of about 310 g/L. The content of volatile matter was 4% (amountlost at 105° C. for 2 hours). Subsequently, 78 parts of the particlesand 3 parts of zeolite 4A (average particle size: about 3 μm) wereintroduced into a High-Speed Mixer (manufactured by Fukae Powtec Corp.,volume capacity: 25 L), and mixed. Thereafter, 5 parts of the samecrystalline alkali metal silicate powders as in Preparation Example 3were introduced into the mixer, and the mixture was further pulverizedand granulated with stirring, with spraying 4 parts of the abovenonionic surfactant thereto. In this process, 5 parts of the abovepowdery zeolite were added for surface-coating immediately before thetermination of the process, to give base detergent granules. The entirecharged amount was 5 kg.

PREPARATION EXAMPLE 7

Ten parts of a sodium linear alkyl(10 to 13 carbonatoms)benzenesulfonate, 15 parts of zeolite 4A, 7 parts of sodiumcarbonate, 5 parts of sodium sulfate, 2 parts of sodium sulfite, and 2parts of the same sodium polyacrylate as in Preparation Example 1(average molecular weight: 10,000) were mixed with water to prepare aslurry having a solid ingredient of 50% by weight (temperature: 58° C.).The resulting slurry was spray-dried by using a countercurrent flow typespray-dryer. The content of volatile matter of the particles was 2%(amount lost at 105° C. for 2 hours). Twenty parts of the same nonionicsurfactant as in Preparation Example 6; 3 parts of the same polyethyleneglycol as in Preparation Example 1; and 7 parts of palmitic acid weremixed with heating at 75° C. to prepare a liquid mixture. Subsequently,30 parts of the above particles, 30 parts of the same crystalline alkalimetal silicate as in Preparation Example 4, and 8 parts of the sameamorphous aluminosilicate as in Preparation Example 4 were introducedinto the same Lödige Mixer as in Preparation Example 4, and the stirringby the main shaft (150 rpm) and the chopper (4,000 rpm) was started. Theabove liquid mixture was supplied to the mixer over a period of 2.5minutes, and thereafter stirred for 6 minutes. Further, 3 parts ofamorphous aluminosilicate was supplied as a surface-coating agent to themixer, and the mixture was stirred for 1.5 minutes, to give basedetergent granules. The entire charged amount was 4 kg.

[Classification Procedures for Base Detergent Granules]

Classification procedures were carried out with each of the basedetergent granules of Preparation Examples 1 to 7 using the classifierdescribed above. Specifically, 100 g/batch of a sample was firstsupplied on a 2,000-μm sieve arranged at top of the classifier.Thereafter, the classifier was capped, and attached to a rotating andtapping shaker machine (manufactured by HEIKO SEISAKUSHO, tapping: 156times/min, rolling: 290 times/min), and vibrated for 10 minutes.Thereafter, the samples remained on each of the sieves and a receivingtray were individually collected to obtain necessary amounts of samplesof each group of the classified granules having sizes of 1,410 to 2,000μm, 1,000 to 1,410 μm, 710 to 1,000 μm, 500 to 710 μm, 355 to 500 μm,250 to 355 μm, 180 to 250 μm, 125 to 180 μm, and ones on the tray to 125μm (less than 125 μm).

[Classification Procedures for Enzyme Granules]

The same classification procedures as those of the base detergentgranules were carried out for Enzyme Granules A (manufactured by NOVONordisk, Savinase 18T Type W), to give each of the classified enzymegranules.

[Classification Procedures for Crystalline Alkali Metal Silicate]

The same classification procedures as those of the base detergentgranules were carried out for Crystalline Alkali Metal Silicate B(manufactured by Clariant, SKS-6 granules), to give each of theclassified enzyme granules.

[Determination of Dissolving Rate Vi of Each of Classified Granules]

The dissolving rate of each group of the classified granules wasdetermined in accordance with the determination method described above.The results are shown in Table 1.

TABLE 1 Crystalline Prep. Prep. Prep. Prep. Prep. Prep. Prep. EnzymeAlkali Metal Vi Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 A Silicate B V[1410–2000 μm] 44.8 48.2 44.5 59.9 45.9 44.8 45.8 — — V [1000–1410 μm]53.8 58.9 54.6 70.5 52.3 49.8 55.1 59.4 — V [710–1000 μm] 64.1 67.8 61.584.3 65.1 64.0 64.4 74.4 — V [500–710 μm] 77.6 82.3 78.3 97.6 79.8 77.678.5 81.3 85.6 V [355–500 μm] 95.4 98.2 96.8 99.7 96.4 95.2 96.1 95.088.1 V [250–355 μm] 99.6 99.6 99.5 99.8 99.4 98.7 99.5 99.7 94.5 V[180–250 μm] 100 100 100 100 100 99.8 100 — 99.8 V [125–180 μm] 100 100100 100 100 100 100 — 99.9 V [Less than 125 μm] 100 100 100 100 100 100100 — 100

TEST EXAMPLE 1

Detergent compositions were obtained using the classified granules ofthe base detergent granules of Preparation Examples 1 to 7, EnzymeGranules A or the crystalline alkali metal silicate by adjustingparticle size distribution in accordance with the following process.

Operation 1 for Adjusting Particle Size Distribution

Each of the classified granules was weighed so that each sample weighs200 g in accordance with a mass base frequency distribution of theparticle size shown in Table 2, and each sample was mixed for 2 minutesby a rocking mixer (manufactured by Aichi Electronics Co., Ltd.) toprepare various detergent compositions of which particle size wasadjusted.

The detergent compositions shown in Table 2 were evaluated in accordancewith the Evaluations 1, 2 and 4. As a result, in the detergentcompositions I (Examples 1 to 9, 12 and 13), it has been found thatExamples 1, 4, 5, 8 and 12 satisfying the formula (A) of Σ(Wi·Vi)≧95(%)and having a mass base frequency of the classified granules having sizesof less than 125 μm of 0.1 or less were excellent in the dissolubility,the dispersibility and the hand-washing dissolubility. Also, in thedetergent compositions II (Examples 10, 11 and 14), it has been foundthat Examples 10 and 14 satisfying the formula (B) of Σ(Wi·Vi)≧97(%) andhaving a mass base frequency of the classified granules having sizes ofless than 125 μm of 0.08 or less were excellent in the dissolubility,the dispersibility and the hand-washing dissolubility. Further, whenExample 10 and Example 14 were compared, Example 14 containing 5% byweight or more of an anionic surfactant comprising a sulfonate wasevidently excellent in the dispersibility.

In addition, the detergency evaluation shown in Table 3 was carried outin accordance with Evaluation 3. As a result, the detergency of Examples1, 4, 5, 8 and 12 that were excellent in the dissolubility, thedispersibility and the hand-washing dissolubility was higher in thedetergent compositions I. Also, the detergency of Examples 10 and 14that were excellent in the dissolubility, the dispersibility and thehand-washing dissolubility was higher in the detergent compositions II.

Further, Examples 1, 4, 8, 12 and 14 satisfying that an amount of sodiumcarbonate was from 1 to 15% by weight and a total amount of sodiumcarbonate and the alkali metal silicate was from 16 to 40% by weight wasmore excellent in the detergency.

TABLE 2 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Base Detergent Prep.Prep. Prep. Prep. Enzyme Prep. Prep. Prep. Granules Used Ex. 1 Ex. 1 Ex.1 Ex. 1 A Ex. 2 Ex. 2 Ex. 2 W [1410–2000 μm] 0.00 0.01 0.00 0.00 0.000.01 0.01 0.00 W [1000–1410 μm] 0.00 0.02 0.00 0.00 0.00 0.02 0.10 0.00W [710–1000 μm] 0.00 0.06 0.00 0.01 0.01 0.06 0.22 0.02 W [500–710 μm]0.01 0.07 0.02 0.04 0.02 0.07 0.26 0.03 W [355–500 μm] 0.13 0.16 0.070.21 0.00 0.16 0.17 0.11 W [250–355 μm] 0.40 0.40 0.14 0.33 0.00 0.400.11 0.18 W [180–250 μm] 0.40 0.18 0.28 0.31 0.00 0.18 0.06 0.24 W[125–180 μm] 0.04 0.08 0.33 0.04 0.00 0.08 0.04 0.26 W [Less than 125μm] 0.02 0.02 0.16 0.03 0.00 0.02 0.03 0.16 Average Particle 259 303 182284 303 565 201 Size [μm] Bulk Density [g/L] 773 770 731 775 821 839 788Flowability [sec] 6.3 6.8 >10 6.4 6.8 6.4 >10 Σ (Wi · Vi) [%] 99 93.999.3 97.0 95.0 83.3 98.6 Evaluation 1 A C A A–B B D A Evaluation 2 I IIIV I II I IV Evaluation 4 [sec] 36 118 31 68 95 250 42 Ex. 12 Ex. 8 Ex.9 Ex. 10 Ex. 11 Crystalline Ex. 13 Ex. 14 Base Detergent Prep. Prep.Prep. Prep. Prep. Alkali Metal Prep. Prep. Granules Used Ex. 3 Ex. 3 Ex.4 Ex. 4 Ex. 5 Silicate B Ex. 6 Ex. 7 W [1410–2000 μm] 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 W [1000–1410 μm] 0.00 0.09 0.00 0.04 0.00 0.000.00 0.00 W [710–1000 μm] 0.04 0.20 0.03 0.14 0.00 0.00 0.00 0.00 W[500–710 μm] 0.09 0.19 0.10 0.15 0.02 0.02 0.01 0.01 W [355–500 μm] 0.250.14 0.26 0.16 0.18 0.02 0.08 0.07 W [250–355 μm] 0.23 0.12 0.30 0.160.36 0.01 0.22 0.41 W [180–250 μm] 0.19 0.08 0.21 0.13 0.34 0.00 0.290.44 W [125–180 μm] 0.10 0.08 0.08 0.13 0.04 0.00 0.26 0.05 W [Less than125 μm] 0.10 0.10 0.02 0.09 0.01 0.00 0.14 0.02 Average Particle 296 476312 347 277 202 248 Size [μm] Bulk Density [g/L] 772 769 873 890 752 781779 Flowability [sec] 6.7 6.9 6.0 6.1 6.8 >10 6.3 Σ (Wi · Vi) [%] 95.683.6 99.2 96.2 99.1 99.0 99.3 Evaluation 1 B D A B A A A Evaluation 2 IIII II IV I IV I Evaluation 4 [sec] 90 282 29 75 34 46 29

TABLE 3 Ex. 12 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Ex.10 Ex. 11 Crystalline Ex. 13 Ex. 14 Base Detergent Prep. Prep. Prep.Prep. Enzyme Prep. Prep. Prep. Prep. Prep. Prep. Prep. Prep. AlkaliMetal Prep. Prep. Granules Used Ex. 1 Ex. 1 Ex. 1 Ex. 1 A Ex. 2 Ex. 2Ex. 2 Ex. 3 Ex. 3 Ex. 4 Ex. 4 Ex. 5 Silicate B Ex. 6 Ex. 7 Evaluation 354 46 42 55 48 44 41 52 43 52 41 54 37 56

TEST EXAMPLE 2

Each of the high-density detergent compositions was obtained using theclassified granules of the base detergent granules (1) of PreparationExample 1 by adjusting particle size distribution in accordance with thefollowing process.

Operation 2 for Adjusting Particle Size Distribution

One-hundred parts of the base detergent granules (1) obtained inPreparation Example 1 were classified by a gyratory screen (manufacturedby Tokuju Kosakusho) having a screen having a 500 μm-sieve opening. Thesieve-on granules were removed to give 55.3 parts of the detergentcomposition of Example 15.

Operation 3 for Adjusting Particle Size Distribution

The amount 55.3 parts of the detergent composition of Example 15 wasintroduced as base detergent granules into a gyratory screen having ascreen having a 125 μm-sieve opening to remove fine powder having a sizeof less than 125 μm, thereby giving 51.5 parts of the detergentcomposition of Example 16.

Operation 4 for Adjusting Particle Size Distribution

In the same manner as in Operation 2 for adjusting particle sizedistribution, 100 parts of the base detergent granules (1) obtained inPreparation Example 1 were introduced into a gyratory screen having ascreen having a 500 μm-sieve opening, and classified into sieve-ongranules A and sieve-pass granules A, wherein the weights thereof were44.7 parts and 55.3 parts, respectively. The amount 44.7 parts of thesieve-on granules A and 2 parts of powdery zeolite (average particlesize: 3 μm) as an aid agent for pulverization were fed into a Fitz Mill(manufactured by Hosokawa Micron Corporation) with cooling air, to givea first-step pulverized granules. Thereafter, the first-step pulverizedgranules were fed into the second step of the Fitz Mill to givesecond-step pulverized granules. The opening of the screen of the FitzMill for the first-step had a diameter of 2 mm and that for thesecond-step had a diameter of 1 mm. The average particle size of thesecond-step pulverized granules was 376 μm. Of the 48.7 parts of thesecond-step pulverized granules, granules having a size of 500 μm ormore occupied 23.2 parts. The second-step pulverized granules wereintroduced into the above gyratory screen having a screen having a 500μm-sieve opening, and classified into sieve-on granules B and sieve-passgranules B. The amount 25.5 parts of sieve-pass granules B and 55.3parts of the sieve-pass granules A were blended to give 80.8 parts ofthe detergent composition of Example 17.

Operation 5 for Adjusting Particle Size Distribution

The amount 80.8 parts of the detergent composition of Example 17 wasintroduced into the above gyratory screen having a screen having a 125μm-sieve opening to remove fine powder having a size of less than 125μm, thereby giving 76.0 parts of the detergent composition of Example18.

Operation 6 for Adjusting Particle Size Distribution

The amount 80.8 parts of the detergent composition of Example 17 wasintroduced into a gyratory screen having a screen having a 180 μm-sieveopening, and classified into sieve-on granules C and sieve-pass granulesC. The weights of the sieve-on granules C and the sieve-pass granules Cwere 65.4 parts and 15.4 parts, respectively.

The sieve-pass granules C were granulated according to the followingprocedures. The amount 15.4 parts of the sieve-pass granules C wasintroduced into the above High-Speed Mixer, and 0.77 parts of the abovenonionic surfactant was sprayed thereto over a period of 1.3 minutes.Thereafter, the mixture was granulated with stirring for 10 minutes.Subsequently, the resulting granules were subjected to a surface-coatingtreatment for 1 minute by adding 0.92 parts of zeolite (average particlesize: about 3 μm), to give base detergent granules (2) (average particlesize: 662 μm). The base detergent granules were classified into sieve-ongranules A′ and sieve-pass granules A′ using a gyratory screen having a500 μm-sieve opening. The sieve-on granules A′ were subjected totwo-step pulverizing, the same method as used in Operation 4, using aFitz Mill to classify the resulting pulverized granules into sieve-ongranules B′ and sieve-pass granules B′ using a gyratory screen having a500 μm-sieve opening. Thereafter, the sieve-pass granules B′, thesieve-pass granules A′ and the sieve-pass granules C were blended togive 80.0 parts of the detergent composition of Example 19.

Each of the detergent compositions shown in Table 4 was evaluated inaccordance with the Evaluations 1, 2 and 4. As a result, it has beenfound that Examples 15 to 19 were excellent in the dissolubility, thedispersibility and the hand-washing dissolubility. Here, it has beenfound that Examples 16, 18, and 19 having a low mass base frequency ofthe classified granules having sizes of less than 125 μm wereparticularly excellent in the dispersibility. In addition, thedetergency evaluation shown in Table 5 was carried out in accordancewith the Evaluation 3. As a result, it has been found that Examples 15to 19, which were excellent in the dissolubility and the dispersibility,were also excellent in the detergency.

TABLE 4 Ex. 15 Ex. 16 Ex. 17 Ex. 18 Ex. 19 Base Detergent Prep. Prep.Prep. Prep. Prep. Granules Used Ex. 1 Ex. 1 Ex. 1 Ex. 1 Ex. 1 W[1410–2000 μm] 0.00 0.00 0.00 0.00 0.00 W [1000–1410 μm] 0.00 0.00 0.000.00 0.00 W [710–1000 μm] 0.00 0.00 0.00 0.00 0.00 W [500–710 μm] 0.000.00 0.00 0.00 0.00 W [355–500 μm] 0.14 0.15 0.30 0.30 0.30 W [250–355μm] 0.31 0.34 0.28 0.32 0.36 W [180–250 μm] 0.31 0.33 0.24 0.24 0.29 W[125–180 μm] 0.17 0.18 0.13 0.14 0.04 W [Less than 125 μm] 0.07 0.000.05 0.00 0.01 Average Particle Size 237 248 276 285 292 [μm] BulkDensity [g/L] 701 730 715 708 704 Flowability [sec] 7.3 6.5 6.7 6.2 6.3Σ (Wi · Vi) [%] 99.2 99.2 98.5 98.5 98.5 Evaluation 1 A A A A AEvaluation 2 II I I I I Evaluation 4 [sec] 27 29 38 48 55

TABLE 5 Ex. 15 Ex. 16 Ex. 17 Ex. 18 Ex. 19 Base Detergent Prep. Prep.Prep. Prep. Prep. Granules Used Ex. 1 Ex. 1 Ex. 1 Ex. 1 Ex. 1 Evaluation3 56 58 55 57 59

TEST EXAMPLE 3

The data on the dissolubility of the granules and the hand-washingdissolubility for 17 kinds of commercial products of representativedetergent compositions sold in Japan and elsewhere are shown in Table 6.

It is clear from the results shown in Table 6 that these marketeddetergents are low in level of the dissolubility of the granules, andalso poor in the hand-washing dissolubility.

TABLE 6 Time Period of Σ (Wi · Vi) hand-washing [%] solution [s] JapanMarketed Detergent A 88.8 160 Marketed Detergent B 83.7 185 MarketedDetergent C 93.4 131 Marketed Detergent D 83.8 205 Marketed Detergent E89.5 178 Marketed Detergent F 91.7 168 Marketed Detergent G 84.2 202Marketed Detergent H¹⁾ 95.4 152 Europe and America Marketed Detergent I94.0 119 Marketed Detergent J 90.9 173 Marketed Detergent K 92.5 172Marketed Detergent L 93.8 185 Asia and Oceania Marketed Detergent M 81.2227 Marketed Detergent N 84.1 245 Marketed Detergent O 74.5 155 MarketedDetergent P 80.1 190 Marketed Detergent Q 91.7 232 ¹⁾Anionic surfactant:nonionic surfactant = 2:21

INDUSTRIAL APPLICABILITY

The detergent composition of the present invention rapidly dissolvesafter supplying to water, even with cold water, is excellent in thedispersibility owing to agglomeration of the granules, and is excellentin detergency such that the detergent composition exhibits excellentdissolubility and detergency under washing conditions of low-mechanicalpower as employed in recent washing machines, and further even underwashing conditions such as hand-washing.

EQUIVALENT

Those skilled in the art will recognize, or be able to ascertain usingsimple routine experimentation, many equivalents to the specificembodiments of the invention described in the present specification.Such equivalents are intended to be encompassed in the scope of thefollowing claims.

1. A high-density detergent composition comprising 10 to 60% by weightof a surfactant composition having a weight ratio of an anionicsurfactant to a nonionic surfactant of 4:10 or more and 10:0 or less,wherein said surfactant composition comprises an alkali metal silicateand also comprises 15% or less by weight of sodium carbonate, whereinthe high-density detergent composition has a bulk density of from 600 to1200 g/L, and has a total summation of a product of a mass basefrequency Wi and a dissolving rate Vi which satisfies the followingformula (A):Σ(Wi·Vi)≧95(%)  (A) of each group of classified granules obtained byclassifying detergent granules by using a classifier, wherein a massbase frequency Wi of the classified granules having a size of less than125 μm is 0.1 or less and a mass base frequency Wi of the classifiedgranules having a size of more than 710 μm and less than 1000 μm is 0.1or less and each mass base frequency Wi satisfies the relationship suchthat the mass base frequency of [classified granules having a particlesize of 1000 μm or more]≦[classified granules having a particle size of710 μm or more and less than 1000 μm]≦[classified granules having aparticle size of 500 μm or more and less than 710 μm] when the granulesare classified with a classifier that comprises a series of sieveshaving sieve-openings respectively of 2000 μm, 1410 μm, 1000 μm, 710 μm,500 μm, 355 μm, 250 μm, 180 μm, and 125 μm, and a receiver, wherein themass base frequency Wi is obtained by dividing the weight of theclassified granules on each sieve or on the receiver by an entire weightof the detergent composition, and wherein the dissolving rate Vi isdetermined under the following measurement conditions: supplying 1.000g±0.010 g of a sample to 1.00 L±0.03 L of water at 5° C.±0.5° C. havinga water hardness of 4° DH, stirring in a 1 L beaker of which innerdiameter is 105 mm, with a cylindrical stirring rod of which length is35 mm and diameter is 8 mm, at a rotational speed of 800 rpm for 120seconds, and thereafter filtering insoluble remnants by a standard sievehaving a sieve-opening of 300 μm as defined according to JIS Z 8801,wherein the dissolving rate Vi of the classified granules is calculatedby the following formula (a), i being each group of the classifiedgranules:Vi=(1−Ti/Si)×100(%)  (a) wherein Si is a weight (g) of each group of theclassified granules supplied; and Ti is a dry weight (g) of theinsoluble remnants of each group of the classified granules remaining onthe sieve after filtration.
 2. A high-density detergent composition asin claim 1, wherein the counterions in said anionic surfactant comprise5% by weight or more potassium counterions.
 3. A high-density detergentcomposition as in claim 2, wherein said anionic surfactant comprises 1to 50% by weight of said detergent composition.
 4. A high-densitydetergent composition as in claim 3, wherein said anionic surfactantcomprises 5 to 30% by weight of said detergent composition.
 5. Ahigh-density detergent composition as in claim 1, wherein said nonionicsurfactant is a polyoxyethylene-polyoxypropylene-polyoxyethylene alkylether.
 6. A high-density detergent composition as in claim 1, wherein atotal sum of the sodium carbonate and the alkali metal silicate is 19%or more by weight of the detergent composition.
 7. The high-densitydetergent composition of claim 1, wherein the alkali metal silicatecomprises SiO₂ and M₂O, wherein M represents an alkali metal atom, andthe SiO₂/M₂O mole ratio in said alkali metal silicate is from 0.5 to2.6.
 8. The high-density detergent composition of claim 1, wherein saidalkali metal silicate is crystalline.
 9. The high-density detergentcomposition of claim 1, wherein said alkali metal silicate isrepresented by formula (I) or formula (II):x(M₂O).y(SiO₂).z(Me_(m)O_(n)).w(H₂O)  (I)M₂O.x′(SiO₂).y′(H₂O)  (II) wherein, in formula (I) M stand for anelement in Group IA of the Periodic Table, Me stand for one or moreelements selected from Group IIA elements, Group IIB elements, GroupIIIA elements, Group IVA elements, and Group VIII elements of thePeriodic Table, y/x is from 0.5 to 2.6, z/x is from 0.001 to 1.0, w isfrom 0 to 20, and n/m is from 0.5 to 2.0, and in formula (II) M standsfor an alkali metal, x′ is from 1.5 to 2.6, and y′ is from 0 to
 20. 10.The high-density detergent composition of claim 1, wherein said anionicsurfactant comprises 1 to 50% by weight of said detergent composition,and wherein said surfactant composition comprises 0.5 to 40% by weightof a crystalline silicate.
 11. A process for preparing the high-densitydetergent composition of claim 1 comprising subjecting unclassifieddetergent granules comprising 10 to 60% by weight of a surfactantcomposition, having a weight ratio of anionic surfactant to nonionicsurfactant of 4:10 or more and 10:0 or less, to classificationoperation; and adjusting a particle size of each group of the resultingclassified granules, such that the formula (A) is satisfied, and suchthat a mass based frequency of the classified granules having a size ofless than 125 μm is 0.1 or less.